Crown block



Nov. 12, 1935- H. P. wlcKERsl-IAM ET Al.

CROWN BLOCK Filed Aug and Patented Nov. 12, 1935 PATENT OFFICE CROWN BLOCK Harry P. Wickersham, Huntington Park, and Erwin Burns, Los Angeles, Calif.

Application August 7, 1935, Serial No. 35,107

4 Claims.

This invention has to do with hoisting equipment and has particular reference to a crown block for use on a well derrick. A general object of this invention is to provide a simple, sturdy 5 and compact crown block.

The crown blocks employed on the derricks of oil Wells and gas wells are usually quite complicated structures embodying a large number of separable parts. For example, a. typical crown block includes, in addition to the shafts and sheaves, separable bearings for the shafts, spacers on the shafts between the sheaves, spacer plates, tie rods, beams or supports, etc. The inclusion of these many parts makes the typical crown blocks very expensive and, of. course, adds to their` size and weight.

Another object of this invention is to provide a crown block that embodies a minimum number of parts and is, therefore, simple and inexpensive.

Another object of this invention is to provide a crown block that embodies a simple, one piece or integral body for carrying a plurality of sheave supporting shafts. l

Another object of this invention is to provide a crown block embodying a unitary base or body structure having spaced supports or beam parts for carrying the shafts whereby the shaft of each individual sheave may be supported on two spaced beam parts.

Another object of this invention is to provide a crown block of the character mentioned embodying a plurality of sheaves spaced and grouped to properly handle the cables or lines.

Another object of this invention is to provide a crown biock that embodies a simple effective cover or guard that extends over and shields the several sheaves and prevents. the lines from escaping or jumping from the sheaves.

The various objects and features of our inven-v tion will be fully understod'from the following detailed description of typical preferred forms and applications of our invention, throughout which description reference is made to the accompanying drawing, in which:

Fig. 1 is a side elevation ofthe improved crown block of this invention. Fig. 2 is a top or plan view of the crown block with the guard removed and Fig. 3 is a transverse detailed sectional view of the crown block taken in the plane of the central sheave.

The improved crown block provided by our present invention includes, generally a body I0, a plurality of sheaves I i mounted on the body I, and a cover or guard I2 on the body for shielding the sheaves.

The body I0 is in the nature of. a. frame for carrying the several sheaves II and is adapted to be mounted or arranged on the head or water table of a well derrick. The construction and formation .of the body l0 are important features 5 of the invention. In accordance with the invention the frame or body I0 is a unitary or onepiece casting or member. 'I'he Vbody I0 is a substantially rectangular Abox-like structure cornprising spaced vertical sides I3 and spaced verti- 10 cal ends I4 extending between and integrally joining the sides. The sides I3 of the body it have the conguration of Ibeams, being provided with base flanges I`5 and top iianges IG projecting horizontally in both directions from their bodies or 15 webs. The sides I3 project or extend outwardly beyond the opposite ends VIt to have wing extensions or Wings I1. The base flanges l5 of the wings 'I'I may be thickened to rest on supports of the derrick to carry the crown block. 20 The outer edges or ends of the wings I'I are preferably flanged and are inclined or curved downwardly `and outwardly as clearly shown in Fig. 1 of `the drawing. The body ends M have top flanges I8 in the same plane as the top flanges I5 25 of the sides, the upper surfaces of the flanges I6 and I8 preferably forming continuous regular horizontal faces or surfaces. Outwardly projecting flanges I9 extend along the lower edges of the ends Il! and their opposite ends join the inner 30 base anges I5 of the wings Il.

In accordance with the invention a plurality of spaced beam parts or sheave supporting partitions 2i! extend across the interior of the body I. The beam parts or partitions 20 are integral 35 parts of the unitary body It. The number and the relative positions of the partitions 2S depend to a large extent upon the number and character of the sheaves embodied in the crown block. In the typical form of the invention shown in the 40 drawing there are two sheave supporting partitions ZE?. The beam parts or partitions 2t are vertical and extend between the body ends Id being integrally joined with the ends. The partitions 2G may be of the same cross sectional con- 45 figuration as the sides IIS having base iianges 2i and top flanges 22. The upper surfaces of the top flanges '22 are preferably in the same horizontaf. plane as the upper surface of the fianges It and I8. The compartment or space between 50 the two partons 2G may be of the same width as `the spaces between the partitions and the adjacent sides I3. The lower end ofthe body I 0 is open, that is, the lower .end of the body is open between the base flanges 2| of the partitions 20 55 and between the base flanges 2| and the flanges I5 of the adjacent sides I3. The upper ends of the sides I3 and the partitions 2i) are formed with recesses or seats for carrying the sheave supporting shafts as will be hereinafter described. It is to be noted that the body Iii just described is a simple one-piece structure having a high degree of strength and rigidity for the parts and material involved. Y

The sheaves I I are provided to carry or handle the lines employed in the well derrick. The number and relative sizes of the sheaves II may depend upon the requirements of the particular use or installation of the crown block. In the form of the invention shown in the drawing there are` live sheaves II of equal effective diameter.V In the arrangement or relative disposition of the sheaves illustrated there is a central sheave I I supported on the two partitions 26 Vand two` posed transverse of the sides I3 and partitions 30 sheaves II at the other side of the block. Partially cylindrical grooves or bearing seats 29 are provided in the upper sides or flanges It and 22 of the sides I3 and partitions 20 for receiving the end portions of the shafts 21. The flanges 22 of the partitions 2|! have elevated or upwardly exleaving'or providing intermediate portions 32 of of the shafts. 55

bricant may be readily supplied to larger diameter for carrying the anti-friction bearings 28. The ends of the enlarged portions 32 of the shafts are adapted to cooperate with the thrust anges 3| to limit the endwise' movement Suitable caps 33 are bolted or otherwise secured to the flanges lrand 22 and the portions 39 to retain the shafts 2'| on the seats 29. The caps 33 preferably have thrust flanges 34 similar to the thrust flanges 3|. The invention provides lubricant ports 35 in the shafts 2. The ports 35 extend from the outer ends of the shafts to the bearings 23 and lubricant receiving fittings 35 are provided at the outer ends of the ports whereby grease or other luthe bearings 28.V Y Y The cover or guard I2 is provided to protect the sheaves II and to prevent the lines from jumping or escaping from the sheaves. In ac- 1 cordance with the invention the guard I2 is a simple one-piece member extending between the flanges I 8 of the body ends IB. In the construction illustrated the guard I2 is arched or curved to Vpass above the several sheaves II with desirable clearance, it being understood that the shape of the guard I2 may be varied somewhat to acy comodate sheaves of different diameters and arrangement. Downwardly projecting inclined lips III may be provided on the outer top flanges I8 of the ends I4Vand the edge or end portions of the guard I2 may be secured to these lips by bolts orscrews 4I. In accordance with the invention the guard I2 passes over the sheaves II in relatively close proximity to their upper peripheral portions to prevent the lines from jumping or escaping from the grooves 26. The central sheave II having its axis of rotation spaced above the axes o f rotation of the other sheaves II has its upper peripheral portion adjacent the inner side of the guard I2 so that the guard arched as described above is effective in preventing the escape of the line from the center sheave as well as the othersheaves. f

It is believed that the utility and practicability of the crown block of the present invention will be readily apparent from the foregoing'V detailed description. The crown block of the invention is particularly simple embodying only the integral body II) and the guard I2 in addition to the sheaves and their shafts. The integral or onepiece body Ii) constitutes the base or frame of the crown block and carries the individual shafts 2'| of the several sheaves II. The body I0 may be readily mounted and secured on the head or water table of the derrick, its wings I'I constituting simple effective mounting parts. As the sheaves I I are carred for rotation by the anti-friction bearings 28 the shafts 2`| do not rotate and the body seats 29 are not worn. The sheaves VII are spaced and related for the proper handling VAof the lines and the body I0 is such that the sheaves may be arranged in a small compact group. The sheave supporting shafts 2'| supported as described above are dependably carried on the beam like sides I3 and partitions 20 of the body. The lines passing over the sheaves II are free to pass downwardly through the spaces between the base flanges I5 and 2|. The simple cover or guard I2 in addition to effectively shielding the sheaves II prevents the escape of the lines from the sheaves.

The enlarged portions 32 of the shafts 2`| provide extensive surfaces for the bearings 29 and operateV to limit endwise movement of the shafts. The supporting or mounting of the sheaves II embodies a minimum number of simple dependable parts. The box like body I Ihaving the partitions 20 extending through its interior is very rigid and-strong.

Having described only a typical preferred form and application of our invention, we do not wish to be limited or restricted to Vthe specific details herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art or-fall within the scope of the following claims:

Having described our invention, We claim:

1. A crown block including a frame, a substantially centrally disposed shaft carried by the frame, outer shafts carried by the frame at points spaced below and outwardly from the first mentioned shaft, sheaves on the shafts, and an arched guard on therframe extending over the sheaves in relatively close proximity to their rims to prevent the escape of lines from the sheaves.

2. In a crown block, an integral body comprising spaced sides, spaced ends connecting the sides, and spaced parts extending between the ends. elevated bearing seats on the spaced parts, a shaft carried in the seats. aligned bearing seats on the sides and the adjacent parts, shafts carried in the last named seats, and sheaves on the shafts.

3. A crown block including an integral body comprising spaced ends, spaced sides connecting the ends, and partition parts extending across the interior of the body, shafts supported on the sides and said parts, sheaves on the shafts, and integral thrust flanges on the sides and parts to limit endwise movement of the sheaves.

4. A crown block including an integral body comprising spaced ends, spaced sides connecting the ends, and partition parts extending across the interior of the body, shafts having their end portions supported by the sides and parts and having intermediate portions of enlarged diameter, sheaves rotatably supported on the enlarged portions, and integral thrust flanges on the sides and parts engageable by said enlarged portions.

ERWIN BURNS.

HARRY P. WICKERSHAM. 

